To find the roots of the quadratic equation

Description:

Nature of roots of quadratic equation can be known from the quadrant ê = b²-4ac

If  b²-4ac >0 then roots are real and unequal

If  b²-4ac =0 then roots are real and equal

If  b²-4ac <0 then roots are imaginary

Algorithm:

Step 1: start

Step 2: read the a,b,c value

Step 3: if (b*b-4ac)>0 then

                        Root 1= (-b+ pow((b*b-4*a*c),0.5))/2*a

Root 2= (-b-pow((b*b-4*a*c),0.5))/2*a

Step 4: if (b*b-4ac)=0 then

                        Root1 = Root2 = -b/(2*a)

Step 5: Otherwise Print Imaginary roots. Goto step 7.

Step 6: print roots

Step 7: stop

 

Program:

 #include<stdio.h>

#include<math.h>

void main()

{

float a,b,c,r1,r2,d;

clrscr();

printf("Enter the values for equation:");

scanf("%f%f%f",&a,&b,&c);

/* check the condition */

if(a==0)

printf("Enter value should not be zero ");

else

{

             d=b*b-4*a*c;

/* check the condition */

  if(d>0)

            {

                        r1=(-b+sqrt(d)/(2*a));

                         r2=(-b-sqrt(d)/(2*a));

                         printf("roots are real and unequal\n");

                         printf("%f\n%f\n",r1,r2);

             }

  else

  if(d==0)

            {

                        r1=-b/(2*a);

                         r2=-b/(2*a);

                         printf("roots are real and equal\n");

                         printf("root=%f\n",r1);

                          printf("root=%f\n",r2);

  }

             else

                         printf("roots are imaginary");

    }

    getch();

}

Output:

1. Enter the values for equation: 1, 6, 9

    Roots are real and equal

    Root= -3.0000

     Root= -3.0000

2. Enter the values for equation: 2, 7, 6

     Roots are real and unequal

    Root= -6.75

    Root= -7.25

3. Enter the values for equation: 1, 2, 3

    Roots are imaginary

Conclusion: The program is error free

VIVA QUESATIONS:

1) What are various types of loop statements?

Ans :    While, do- while, for loop statements

4)      What is the difference between while and do-while statements?

Ans:     In while the condition will be checked first and then enter into a loop.

             But in do- while the statements will be executed first and then finally check the 

             Condition.

3)   How to find the roots of qudratric equtations ?

Ans:  Nature of roots of quadratic equation can be known from the quadrant

          ê =    b²-4ac

If  b²-4ac >0 then roots are real and unequal

If  b²-4ac =0 then roots are real and equal

            If  b²-4ac <0 then roots are imaginary

4) List out the C features ?

Ans: Portability,flexibility, wide acceptability etc..,